That's an interesting/cool finish. Yours seem darker than what I remember black chrome to be though. I believe these faces were plated in black chrome and the lips of course are chrome.

 

my black chrome "painted" varrstoens look a lot more like the centers of those wheels. the op's wheels are dark, but i think they look good. i wish i could get a powdercoated finish that looked like the gtr wheels but no luck as of yet.